Abstract: A method for determining a mean cell volume for a blood sample includes: illuminating the sample with incident light at a plurality of illumination wavelengths and obtaining a two-dimensional image of the sample at each of the plurality of illumination wavelengths; identifying a plurality of cells that appear in each of the images; for each one of the plurality of cells, determining an integrated optical density corresponding to each of the plurality of illumination wavelengths; for each one of the plurality of cells, determining a cell volume based on the integrated optical densities corresponding to each of the plurality of illumination wavelengths; and determining the mean cell volume for the blood sample from the cell volumes for each one of the plurality of cells.

Abstract: Methods for dispensing a fluid sample on a substrate include obtaining an image of a sample applicator in proximity to the substrate, where the image includes a first image of the sample applicator and a second image of the sample applicator, determining a height of the sample applicator relative to a surface plane of the substrate based on a distance between common portions of the first and second images, and dispensing the fluid sample onto the substrate using the sample applicator, where the dispensing includes: translating the sample applicator, translating the substrate, or translating both the sample applicator and the substrate to effect a relative translation between the sample applicator and the substrate; and maintaining the sample applicator within 2 microns of a target height relative to the surface plane of the substrate during the translating.

Abstract: A method for determining a mean cell volume for a blood sample includes: illuminating the sample with incident light at a plurality of illumination wavelengths and obtaining a two-dimensional image of the sample at each of the plurality of illumination wavelengths; identifying a plurality of cells that appear in each of the images; for each one of the plurality of cells, determining an integrated optical density corresponding to each of the plurality of illumination wavelengths; for each one of the plurality of cells, determining a cell volume based on the integrated optical densities corresponding to each of the plurality of illumination wavelengths; and determining the mean cell volume for the blood sample from the cell volumes for each one of the plurality of cells.

Abstract: A method for determining a mean cell volume for a blood sample includes: illuminating the sample with incident light at a plurality of illumination wavelengths and obtaining a two-dimensional image of the sample at each of the plurality of illumination wavelengths; identifying a plurality of cells that appear in each of the images; for each one of the plurality of cells, determining an integrated optical density corresponding to each of the plurality of illumination wavelengths; for each one of the plurality of cells, determining a cell volume based on the integrated optical densities corresponding to each of the plurality of illumination wavelengths; and determining the mean cell volume for the blood sample from the cell volumes for each one of the plurality of cells.

Abstract: A method of determining a volume of a platelet includes: (a) illuminating the platelet with incident light at a plurality of illumination wavelengths; (b) obtaining at least one two-dimensional image of the platelet corresponding to each illumination wavelength; (c) for each illumination wavelength, determining a mean optical density and a maximum optical density for the platelet; (d) determining an area of the platelet; (e) for each illumination wavelength, determining a volume of the platelet; (f) for each illumination wavelength, determining an integrated optical density for the platelet; and (g) determining the volume of the platelet based on a weighted combination of the area of the platelet, the volumes of the platelet corresponding to each of the illumination wavelengths, and the integrated optical densities for the platelet corresponding to each of the illumination wavelengths.

Abstract: Methods and systems for identifying reticulocytes in a blood sample deposited on a substrate include: illuminating the sample with incident light at two different wavelengths, obtaining a two-dimensional image of the sample corresponding to a first one of the wavelengths, and obtaining a two-dimensional image of the sample corresponding to a second one of the wavelengths; analyzing the images to identify a set of representative red blood cells; determining an area of each of the red blood cells in the set; determining a color value of each of the red blood cells in the set; and, for each one of the red blood cells in the set, identifying the red blood cell as a reticulocyte if the area of the red blood cell exceeds an area cutoff value and the color value of the red blood cell is less than a color cutoff value.

Abstract: Systems and methods for positioning a sample applicator relative to a substrate include: (a) obtaining an image of the sample applicator in proximity to the substrate, where the image includes a direct image region corresponding to the sample applicator and a first reflected image region corresponding to an image of the sample applicator reflected from a surface of the substrate; (b) determining a position of an edge of the sample applicator in the direct image region; (c) determining a position of a reflected edge of the sample applicator in the first reflected image region; (d) determining a distance between the edge of the sample applicator and the reflected edge of the sample applicator; and (e) determining the position of the sample applicator relative to the substrate based on the distance between the edges.

Abstract: Systems and methods for displaying measured values of a complete blood count (“CBC”) parameter include displaying the measured values of the CBC parameter obtained from a plurality of samples from a first lot of a quality control composition, where the displaying includes displaying a marker corresponding to each measured value from the first lot on a plot that includes a two dimensional coordinate system, and where the two dimensional coordinate system includes a first dimension corresponding to a time at which measured values of the CBC parameter were obtained, and a second dimension corresponding to a numerical value of the CBC parameter.

Abstract: A method of determining a hemoglobin content value of a red blood cell includes: (a) illuminating the cell with incident light at a plurality of illumination wavelengths; (b) obtaining at least one two-dimensional image of the cell corresponding to each illumination wavelength; (c) for each illumination wavelength, determining a mean optical density and a maximum optical density for the cell; (d) determining an area of the cell; (e) for each illumination wavelength, determining a volume of the cell; (f) for each illumination wavelength, determining an integrated optical density for the cell; and (g) determining the hemoglobin content value of the cell based on the area of the cell, the volumes of the cell corresponding to each of the illumination wavelengths, and the integrated optical densities for the cell corresponding to each of the illumination wavelengths.

Abstract: A method of determining a volume of a platelet includes: (a) illuminating the platelet with incident light at a plurality of illumination wavelengths; (b) obtaining at least one two-dimensional image of the platelet corresponding to each illumination wavelength; (c) for each illumination wavelength, determining a mean optical density and a maximum optical density for the platelet; (d) determining an area of the platelet; (e) for each illumination wavelength, determining a volume of the platelet; (f) for each illumination wavelength, determining an integrated optical density for the platelet; and (g) determining the volume of the platelet based on a weighted combination of the area of the platelet, the volumes of the platelet corresponding to each of the illumination wavelengths, and the integrated optical densities for the platelet corresponding to each of the illumination wavelengths.

Abstract: A method of determining a volume of a platelet includes: (a) illuminating the platelet with incident light at a plurality of illumination wavelengths; (b) obtaining at least one two-dimensional image of the platelet corresponding to each illumination wavelength; (c) for each illumination wavelength, determining a mean optical density and a maximum optical density for the platelet; (d) determining an area of the platelet; (e) for each illumination wavelength, determining a volume of the platelet; (f) for each illumination wavelength, determining an integrated optical density for the platelet; and (g) determining the volume of the platelet based on a weighted combination of the area of the platelet, the volumes of the platelet corresponding to each of the illumination wavelengths, and the integrated optical densities for the platelet corresponding to each of the illumination wavelengths.

Abstract: A method for determining a mean cell volume for a blood sample includes: illuminating the sample with incident light at a plurality of illumination wavelengths and obtaining a two-dimensional image of the sample at each of the plurality of illumination wavelengths; identifying a plurality of cells that appear in each of the images; for each one of the plurality of cells, determining an integrated optical density corresponding to each of the plurality of illumination wavelengths; for each one of the plurality of cells, determining a cell volume based on the integrated optical densities corresponding to each of the plurality of illumination wavelengths; and determining the mean cell volume for the blood sample from the cell volumes for each one of the plurality of cells.

Abstract: A method of determining a hemoglobin content value of a red blood cell includes: (a) illuminating the cell with incident light at a plurality of illumination wavelengths; (b) obtaining at least one two-dimensional image of the cell corresponding to each illumination wavelength; (c) for each illumination wavelength, determining a mean optical density and a maximum optical density for the cell; (d) determining an area of the cell; (e) for each illumination wavelength, determining a volume of the cell; (f) for each illumination wavelength, determining an integrated optical density for the cell; and (g) determining the hemoglobin content value of the cell based on the area of the cell, the volumes of the cell corresponding to each of the illumination wavelengths, and the integrated optical densities for the cell corresponding to each of the illumination wavelengths.

Abstract: Systems, methods and computer program products for mapping coordinates of various imaging stations are described. In some implementations, cells (e.g., red blood cells) in a biological specimen can be used for determining the mapping information between the imaging stations. The use of cells allows a target image (e.g., an image of a sub-region of cells in the biological specimen) taken by one imaging station to be pattern-matched to a reference image (e.g., an image showing a larger region of cells in the biological specimen that also includes the sub-region) taken by another imaging station. Once the target image is matched to the reference image, point by point correspondence (and therefore coordinates) between the target image and the reference image can be established for computing the coordinate transformation to map the imaging stations.